Operational Amplifiers Home / Operational AmplifiersOperational Amplifiers Tutorials Inverting Summing Amplifier using Op Amp The inverting summing amplifier using op amp outputs a voltage equal to the sum of the voltages it has in its inputs. The explanation is based on an adder of three inputs, but applies to an adder of any number of inputsNon-inverting Operational Amplifier How to find the voltage gain (formula) in a non-inverting Op. Amp. How to find the Input impedance (Zi) and output impedance (Zo) of a non-inverting operational amplifier.Operational Amplifier as Comparator Operational Amplifier as Comparator (voltage comparator). Op-Amp can work as comparator when the differential gain in open loop is high and the speed is not a critical factorOp Amp Voltage follower / Voltage Buffer Op-amp voltage follower (op-amp voltage buffer). A buffer has an output that is exactly like the input. This feature is very useful for solving impedance matching problems.Op Amp Open Loop Gain – Op Amp Open Loop Configuration Op Amp Open Loop Gain – Operational Amplifier Open Loop gain is given when there is no feedback path between the output and one of the two inputsHow to use op amps with a single rail power supply? How to use op amps with a single rail power supply? Method #1: Voltage divider using two resistors. Method #2: Voltage divider using two Zener diodes.